Personal electronic devices (e.g. cell phones, PDAs, laptops, gaming devices) provide users with increasing functionality and data storage. Personal electronic devices serve as personal organizers, storing documents, photographs, videos and music, and serving as portals to the Internet and electronic mail. In order to fit within the small displays within such devices, documents (e.g., PDF images and photographs) are typically displayed in a scaling viewer that can be controlled by a zoom function. In order to view all or parts on an image, typical user interfaces permit users to adjust a zoom factor by clicking on a zoom icon, entering a magnification value in a data entry window, or dragging a selection box over the portion to be displayed. Another known user interface mechanism for activating the zoom function is the pinch movement of two fingers on a touchscreen display as implemented on the Apple Computer iPhone®. However, such methods for controlling the zooming function can be difficult to manipulate, particularly to accomplish a deep zoom manipulation of the image. This is particularly the case in small portable computing devices whose usefulness depends upon the zooming function given their small screen size. For example, the small size of the Apple iPhone® display limits the degree to which an image can be zoomed in one step using the two finger pinch movement. Additionally, the high cost of the hardware that enables the two finger pinch zoom renders this method unfeasible in lower cost mobile devices.